1. Field of the Invention
The present invention relates to a non-destructive inspection method and more specifically to such a method which determines the coherence factor between inputted and received waves and which enables the both the presence or absence of a fault and the strength of a joint (or the like), to be ascertained without superficial damage and the like to the item under inspection.
2. Description of the Prior Art
Non-destructive inspection methods have included hammering, X-ray, ultrasonic and the like techniques. These techniques however have suffered from the common drawback that even though cracks can be detected, the actual strength of the joint or element under inspection cannot be ascertained.
The hammering detection technique further encounters the drawback that, when used on a production line, important protective films and coatings tend to be damaged and thus cannot be used with any satisfaction particularly on 100% inspections.
X-ray inspection techniques require extensive shielding in order to protect the health of nearby workers. This of course, apart from providing a potential health hazard increases the cost and complexity of the line.
In the case of ultrasonic detection, noise generated by nearby devices tends to interfere with the accuracy of the system and thus requires special shielding and/or measures to be implemented.